Because most maintainers love it compared to Sys V scripts.

In the end, users might complain about purity of things or something but the mainteners are the ones doing the work maintaining all that and end up deciding what gets used.

Honestly, I'm rather outside of all that stuff and I had my share of problems with systemd issues but that's mostly because I've been using pretty old systems anyway with thus older and buggier versions of the code. And I also remember the pain it was before unit files to get those sys V scripts working correctly. From my perspective, both systems had weird bugs I had to track but systemd clearly wins on the "creating a new service" part.

M$ is pushing hard and not pushing alone

Commercial interests. Linux has benefited greatly from companies adopting it and paying developers but at the same time there has been a price to pay and this kind of thing is it.

Since it's all open source, I think we're reasonably ok because we don't HAVE to do what the commercial distros chose to do.

The problem is if we let it become too difficult. Personally I think a thing like DBUS is needed but dbus itself is undesirable as it adds another IPC type and has no connection to the filesystem or the BSD socket interface or any of the other standard ways that interfaces can be discovered and used. It has a network effect that is not easy to avoid without accepting degradation in the UI.

The more crap we end up accepting the more difficult it becomes to be a lone developer and the more the whole system will turn towards commercial interests and away from what it started out as.